The paylod already as a start header with frame lenght. So normaly the Recv
should be able to re-assemble the data if the data rx in te packet is less then
what the paylod says. Also I am stuck with the defived protocol since it's the
recv how made the requirement.

UDP would required a additionnal layer in my code to deal with packet loss but
this would take care of the segmentation problem.

Thanks
Denis

________________________________

From: netburner_group@yahoogroups.com on behalf of Thomas Taranowski
Sent: Thu 4/2/2009 4:35 PM
To: netburner_group@yahoogroups.com
Subject: Re: [netburner_group] TCP Fragmentation



It sounds like you want to use UDP, as your protocol is structure/datagram
oriented, and your sending packets of data around. TCP doesn't really work that
well for this type of application, as it's stream oriented. You could use a
unique termination string at the end of your packet to indicate EOT for your
data. Your recv()'r can listen for this and assemble what it's received into
your data structure. If you really need to control segmentation, you would need
to hack something into the TCP layer of the stack to control outgoing packet
segmentation in the precise manner you need.


On Thu, Apr 2, 2009 at 12:07 PM, Rheault, Denis <DRheault@...
<mailto:DRheault@...> > wrote:





#1 already do this.

I thought there was a flag I could set in the TCP to stop this..

NULL could still create fragmentation, I will go with you last opinion.
Specially that there is no way for me of controlling the performance of the end
PC..

Thanks



-----Original Message-----
From: netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
[mailto:netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
] On Behalf Of chris ruff

Sent: Thursday, April 02, 2009 2:41 PM
To: netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
Subject: RE: [netburner_group] TCP Fragmentation





Denis:

1. have you tried the trick of

writeall(fd,buf,len)

?

Have you tried punching a bunch of NULLs out after your packet to force the NB
stack to assemble and send a packet

Who is responsible for the Windows end? On the windows apps I write I have
always had to take this very problem into consideration. Basically, everybody
needs to be able to handle packet fragmentation. IMO it is essentially a
marginal hack to force some host to squeak complete packets to make other host
algorithms happy

Chris



-----Original Message-----
From: netburner_group@yahoogroups.com
<mailto:netburner_group@yahoogroups.com>
[mailto:netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
]On Behalf Of Rheault, Denis
Sent: Thursday, April 02, 2009 2:10 PM
To: netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
Subject: RE: [netburner_group] TCP Fragmentation





No, opposite.

The problem I have is that I sent fix length packet of 1224 bytes of payload.
Sometime the receiving end TCP get's full and some fragmentation happen. since
the receiving end (PC) is looking for a fix payload format in the ip frame it
can't recognize the payload data.

What I would like is a way to only send the same type of frame to the PC. For
a unknown reason the Netburner can process faster then the PC. Other thing, I am
not writing the PC application ..

Here is a TCP dump of what happen. 232 is the netburner. Goal is to keep all
packet to 1224



Denis


-----Original Message-----
From: netburner_group@yahoogroups.com
<mailto:netburner_group@yahoogroups.com>
[mailto:netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
] On Behalf Of chris ruff
Sent: Thursday, April 02, 2009 1:30 PM
To: netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
Subject: RE: [netburner_group] TCP Fragmentation





Google "Nagle" algorithm

I am assuming that you want the host computer to send complete packets to
the NB module

Chris




-----Original Message-----
From: netburner_group@yahoogroups.com
<mailto:netburner_group@yahoogroups.com>
[mailto:netburner_group@yahoogroups.com <mailto:netburner_group@yahoogroups.com>
]On Behalf Of Rheault, Denis
Sent: Thursday, April 02, 2009 12:20 PM
To: netburner_group@yahoogroups.com
<mailto:netburner_group@yahoogroups.com>
Subject: [netburner_group] TCP Fragmentation





Hi,

Is there a way I can disable fragmentation in the TCP stack ?

Denis Rheault
Sr. Maintenance Engineering Associate
Telesat
514-528-2207
514-527-6429 fax
drheault@... <mailto:drheault@...>



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--
Thomas Taranowski
Certified netburner consultant
baringforge.com <http://baringforge.com/>